Hi ,
I'm Dyari. Thanks for reaching out. I'm sorry to hear that you are facing this issue.
Have you synced that folder? If you have and deleted it, it will also be deleted from OneDrive.
Make sure you are logged in with the correct account. If you have another account, log in and check if your photos are available there.
If not, go to OneDrive > On the left-hand menu, click Recycle bin > Look for the missing photos and restore them. Files stay there for up to 30 days.
If you ever used the Personal Vault, your files might be there > Sign in to OneDrive > Click Personal Vault from the left menu.